Parfitt Rhodri, Hensman Marianne Y, Lucas Samuel J E
1School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UNITED KINGDOM; 2Centre for Human Brain Health, University of Birmingham, Birmingham, UNITED KINGDOM; and 3Department of Physiology, University of Otago, Dunedin, NEW ZEALAND.
Med Sci Sports Exerc. 2017 Jul;49(7):1305-1312. doi: 10.1249/MSS.0000000000001230.
Aquatic treadmills are used as a rehabilitation method for conditions such as spinal cord injury, osteoarthritis, and stroke, and can facilitate an earlier return to exercise training for athletes. However, their effect on cerebral blood flow (CBF) responses has not been examined. We tested the hypothesis that aquatic treadmill exercise would augment CBF and lower HR compared with land-based treadmill exercise.
Eleven participants completed incremental exercise (crossover design) starting from walking pace (4 km·h, immersed to iliac crest [aquatic], 6 km·h [land]) and increasing 1 km·h every 2 min up to 10 km·h for aquatic (maximum belt speed) or 12 km·h for land. After this, participants completed two 2-min bouts of exercise immersed to midthigh and midchest at constant submaximal speed (aquatic), or were ramped to exhaustion (land; increased gradient 2° every min). Middle cerebral artery blood flow velocity (MCAv) and HR were measured throughout, and the initial 10 min of each protocol and responses at each immersion level were compared.
Compared with land-based treadmill, MCAvmean increased more from baseline for aquatic exercise (21% vs 12%, P < 0.001), while being associated with lower overall HR (pooled difference, 11 bpm; P < 0.001). MCAvmean increased similarly during aquatic walking compared with land-based moderate intensity running (~10 cm·s, P = 0.56). Greater water immersion lowered HR (139 vs 178 bpm for midchest vs midthigh), whereas MCAvmean remained constant (P = 0.37).
Findings illustrate the potential for aquatic treadmill exercise to enhance exercise-induced elevations in CBF and thus optimize shear stress-mediated adaptation of the cerebrovasculature.
水上跑步机被用作脊髓损伤、骨关节炎和中风等疾病的康复方法，并且可以帮助运动员更早地恢复运动训练。然而，其对脑血流量（CBF）反应的影响尚未得到研究。我们检验了这样一个假设，即与陆地跑步机运动相比，水上跑步机运动能增加CBF并降低心率（HR）。
11名参与者完成递增运动（交叉设计），从步行速度（4 km·h，浸入至髂嵴[水上]，6 km·h[陆地]）开始，每2分钟增加1 km·h，直至水上运动达到10 km·h（最大皮带速度）或陆地运动达到12 km·h。在此之后，参与者以恒定的次最大速度浸入至大腿中部和胸部中部完成两段2分钟的运动（水上），或者逐渐增加强度直至力竭（陆地；每分钟增加坡度2°）。全程测量大脑中动脉血流速度（MCAv）和HR，并比较每个方案最初的10分钟以及每个浸入水平的反应。
与陆地跑步机相比，水上运动时MCAvmean较基线增加得更多（21%对12%，P<0.001），同时总体HR较低（合并差异，11次/分钟；P<0.001）。与陆地中等强度跑步相比，水上步行时MCAvmean增加相似（约为10 cm·s，P = 0.56）。更大程度的水浸降低了HR（胸部中部对大腿中部为139次/分钟对178次/分钟），而MCAvmean保持不变（P = 0.37）。
研究结果表明水上跑步机运动有可能增强运动诱导的CBF升高，从而优化剪切应力介导的脑血管系统适应性。
